Why can't I remove the Ask default homepage from my browser?

A number of other browser add-on products (made by other companies) bundle and offer Ask search tools during installation of their products. This includes the Ask default homepage or new tab page, and if not declined at the time of installation, that setting will be changed in your browser.

Normally, this is easily fixed by changing your default homepage or new tab setting back to whatever you'd like it to be. These articles explain how: